Isolation is a defence mechanism in psychoanalytic theory first proposed by Sigmund Freud. While related to repression the concept distinguishes itself in several ways. It is characterized as a mental process involving the creation of a gap between an unpleasant or threatening cognition, and other thoughts and feelings. By minimizing associative connections with other thoughts, the threatening cognition is remembered less often and is less likely to affect self-esteem or the self concept. Freud illustrated the concept with the example of a person beginning a train of thought and then pausing for a moment before continuing to a different subject. His theory stated that by inserting an interval the person was "letting it be understood symbolically that he will not allow his thoughts about that impression or activity to come into associative contact with other thoughts.” As a defense against harmful thoughts, isolation prevents the self from allowing these cognitions to become recurrent and possibly damaging to the self-concept.